Resurrection of Eurya degeneri (Pentaphylacaceae), endemic to Kaua‘i, Hawaiian Islands

<i>Euryadegeneri</i> Kobuski (Pentaphylacaceae), a dioecious shrub endemic to Kaua'i, is resurrected from synonymy with <i>E.sandwicensis</i> A. Gray. <i>Euryadegeneri</i> is distributed in montane mesic to wet forests in central and northwestern Kaua'i. It can be distinguished from <i>E.sandwicensis</i> by its glabrous young stems, leaves and pedicels, linear-elliptic to ovate-elliptic leaves, longer pedicels (5-11 mm long), and shorter petals (4.5-7 mm long). A key to Hawaiian <i>Eurya</i> is provided. Two lectotypes are here assigned. <i>Euryadegeneri</i> is preliminarily designated as Critically Endangered according to the IUCN Red List guidelines.